1. Field of Invention
This invention relates to a wheelchair exercise trainer.
2. Prior Art
A typical prior art trainer provides a pair of elongated rollers set in a frame. A ramp is typically provided so that the chair may be guided up the ramp to a platform with the recessed rollers. FIG. 1 is a perspective view of a typical prior art trainer.
Disadvantages of the prior art device include its large footprint, the expense of the device, and the inability to provide independent wheelchair wheel operation.
Another disadvantage of prior art devices is that they are typically designed for a forward direction only, so that the devices work when the wheelchair wheels are driven in a forward direction, but may not work well when the wheelchair wheels are driven in a reverse direction. Although these forward devices may improve torso and arm strength, they do not provide a balanced exercise regimen to strengthen the back muscles and to lengthen the torso muscles. If the predominant movements are in a forward direction, the back muscles may not be appropriately strengthened, and the torso muscles will have a tendency to constrict. A complimentary backward direction is desirable in order to lengthen the torso muscles.
There is a need for a smaller and less expensive device. There is a need for a device which permits independent wheel operation in both the forward and reverse directions.
U.S. Pat. No. 4,966,362 describes a shallow rectangular frame which supports a pair of free-running elongated rollers parallel to each other and spaced suitably to cradle the main wheels of a conventional wheelchair. A gentle ramp ahead of the rollers enables a wheelchair occupant to drive the wheelchair backwards up the ramp and roll the wheels into the roller cradle. A transverse backstop guards against overrunning the cradle. With the main wheels of the wheelchair in the roller cradle, the front wheels of the chair are supported by the ramp. An adjustable brake at the front roller provides for variable exercising effort and also brakes or locks the roller so that the chair may be easily driven out of the roller cradle and down the ramp.
U.S. Pat. No. 6,645,127 describes an exercise apparatus for a wheelchair which has a raised platform with an upper surface which will support a wheelchair. Front and rear rollers mounted rotatably on the platform project slightly above the platform upper surface to support the driving wheels of the wheelchair. One of the rollers is connected to a flywheel which provides momentum to even out the movement of the rollers and the driving wheels between strokes of the person driving the wheelchair. One or more attachment arms hold the wheelchair immovably on the platform when the user is exercising. The arm is split into two arm sections which rotate relative to one another through a third joint. The outer end of one of the arm sections is pivotally attached to the platform through a first joint and the outer end of the other arm section is pivotally attached to a clamp through a second joint. The clamp is configured to quickly and easily attach to the wheelchair frame. A clamp mechanism causes the first, second and third joints to be simultaneously locked immovably upon the activation of a single handle.
U.S. Pat. No. 6,113,519 describes a treadmill device which includes a braking device incorporated in the body of the treadmill and operated for applying a resistance or load against the rotary motion of treadmill rollers on which a wheelchair's side wheels are supported. The angle of inclination of the treadmill rollers may be adjusted according to any variation in the angle of inclination for the wheelchair wheels supported by the treadmill rollers. To this end, the user of the wheelchair can adjust the angle of inclination for the treadmill rollers. A guide member for supporting the front wheel of the wheelchair may also be included, and the guide member can be adjusted to accommodate practically all types and sizes of the wheelchair. A central control panel is provided at a particular single point on the treadmill for enabling the user of the wheelchair to control the braking device, adjust the angle of inclination, and moving the guide member.
U.S. Pat. No. 5,649,883 describes a trainer for use with a three-wheel racer wheelchair and which may be effectively utilized as part of a computerized system for physiological training and simulated road race training. A jack supports the wheelchair frame such that the drive wheels just make frictional driving contact with the crest of one of two of the trainer's rollers. Undesired drag, caused by the weight of the wheelchair and its user, is substantially decreased or virtually eliminated, enhancing the trainer's ability to simulate real road conditions.
U.S. Pat. No. 5,476,429 describes an exercise device for the occupant of a wheelchair acting as a treadmill which may be used for cardiac stress testing, cardiac or stroke rehabilitation, fitness training, aerobic training or educational/physical games, with the device including a generally inclined ramp having parallel sides, a forward entrance portion, a movable dolly mounted on rails on the sides of the ramp, the dolly having a pair of laterally movable caster capture plates with openings to receive the front casters of a wheelchair and angular rods cooperating with the wheelchair drive wheels acting to adjust the lateral spacing of said plates, locking means for the dolly to retain it in its forward position, separate locking means for locking the dolly in its rearward position when a wheelchair has been moved onto the ramp into operative position, a pair of enlarged openings adjacent the rear edge of the ramp, and a pair of longitudinally movable rollers beneath the ramp and movable between a rear retracted position allowing the wheelchair drive wheels to be partially received in the openings and a forward position under the drive wheels to engage and lift the drive wheels so that the user can manually rotate the wheelchair drive wheels to rotate the rollers and provide signals to a control apparatus for the desired type of training, testing or rehabilitation.
U.S. Pat. No. 5,704,876 describes an aerobic wheelchair trainer with variable resistance. The wheelchair trainer includes a ramp having a plurality of level steps. The steps lead a wheelchair inserted into the wheelchair trainer onto a platform. The wheelchair trainer also includes a support mechanism that supports the weight of the wheelchair and wheelchair occupant. A load mechanism including a resistance roller and an eddy current brake is also included. The load mechanism provides a variable resistance to movement of the wheels of the wheelchair. The wheelchair trainer also includes a lift mechanism that lifts the rear end of the wheelchair up and into or out of the support mechanism. The load mechanism is connected to a controller. The wheelchair trainer may be used either individually or may be connected to another compatible wheelchair trainer over a phone line.
Several physiological studies have been conducted on a Wheelchair Aerobic Fitness Trainer (WAFT) devices. While this device is useful for clinical studies, it is large and expensive. There is a need for a reliable and less expensive device for use in homes, hospitals, and schools.
The WAFT device is described in U.S. Pat. No. 4,911,425. The device includes a pair of ramps each including an open front end and a barriered rear end, it being arranged so that their front ends extended in the same direction and are jointly tiltable between a downwardly inclined forwardly facing position and a level position, with the ramps at their respective rear ends each journaling a plurality of rollers that are flywheel effect equipped and that are spaced apart longitudinally of the respective ramps, which rollers are exposed at the top of the ramps, and including a manually operated mechanism for simultaneously tilting the ramps between a tilted wheelchair receiving position, in which the wheelchair user can back his chair onto the ramps while seated in the wheelchair, with the wheelchair rear wheels reaching and resting on the respective sets of ramp rollers, several of which are braked in the ramp tilted position, and the ramp level position, in which the wheelchair front wheels are braked and the wheelchair user can manually actuate the wheelchair rear wheels for exercise purposes. The rearmost of the respective sets of ramp rollers are equipped to provide independently adjustable resistance at the option of the user.